Packet forwarding in wireless networks

ABSTRACT

A wireless network site comprises a base station and a cell site gateway. The cell site gateway comprises a first interface connected to the base station, a second interface connected to a packet network gateway, a forwarding layer, and a third interface connected to a control server to exchange control plane information. The forwarding layer transmits and receive packets. The control plane information comprises at least one first label value for transmitting a first plurality of packets to the base station and at least one second label value for transmitting a second plurality of packets to the packet network gateway.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/734,754, filed Jan. 4, 2013, which claims the benefit of U.S.Provisional Application No. 61/582,854, filed Jan. 4, 2012, which ishereby incorporated by reference in its entirety.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

An exemplary embodiment of the present invention is described hereinwith reference to the drawings, in which:

FIG. 1 is a simplified block diagram depicting a communication systemfor transmitting and receiving packets to and from a wireless device,according to an exemplary embodiment;

FIG. 2 is a diagram depicting a first example of a wireless network siteaccording to an exemplary embodiment;

FIG. 3 is a diagram depicting a second example of a wireless networksite according to an exemplary embodiment;

FIG. 4 is a simplified diagram depicting connections between a cell sitegateway and a cellular network gateway according to an exemplaryembodiment;

FIG. 5 is a block diagram of a base station and a cell site gatewayaccording to an exemplary embodiment;

FIG. 6 is a block diagram of an integrated architecture for a basestation and a cell site gateway according to an exemplary embodiment;and

FIG. 7 depicts a packet payload and headers according to an exemplaryembodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

The technology disclosed herein is in the technical field of wirelesscommunication systems. More particularly, the technology disclosedherein is related to a method and system for communications in a basestation site for enhancing data traffic transmission employing labelforwarding. Embodiments of the present invention provide a method andsystem for network site in a wireless communication network.

FIG. 1 is a simplified block diagram depicting a communication systemfor transmitting and receiving packets to and from a wireless device 101according to an exemplary embodiment. This simplified block diagramdepicts a system for transmitting data traffic generated by a wirelessdevice 101 to a cellular network gateway 118 over radio interface, forexample employing a multicarrier OFDM radio according to one aspect ofthe illustrative embodiments. As shown, the system includes at its corea packet network gateway 117, which may function to provide connectivityamong one or more cell sites 121, 122 and a cellular network gateway 118and a cellular network signaling node 122. Base stations provideservices to wireless devices 101 (e.g., a cell phone, PDA, or otherwirelessly-equipped device), and may connect them to one or moreservers, such as multimedia server, application servers, email servers,or database servers, or may connect them to other wireless devices. Thepacket network gateway may also be connected via interface 121 to asignaling node 122. Signaling node 122 may provide signaling informationto base stations and wireless devices.

A cell site may include one or more than one base stations connected toa cell site gateway. Base stations in a site may communicate to eachother via the cell site gateway. A base station 105 in cell site 122 maycommunicate with another base station 104 in cell site 121 employingcell site gateways 106 and 107. In such a scenario, cell site gateway106 and cell site gateway 107 may be connected via interface 110 toenable communication between base station 105 and base station 104. Inanother example, the cell site gateway 106 and cell site 107 may beconnected via interfaces 112 and 113 and packet network gateway 117. Anyof the above options may be adopted depending on the operator'spreference and network architecture.

It should be understood, however, that this and other arrangementsdescribed herein are set forth for purposes of example only. As such,those skilled in the art will appreciate that other arrangements andother elements (e.g., machines, interfaces, functions, orders offunctions, etc.) can be used instead, some elements may be added, andsome elements may be omitted altogether. Further, as in mosttelecommunications applications, those skilled in the art willappreciate that many of the elements described herein are functionalentities that may be implemented as discrete or distributed componentsor in conjunction with other components, and in any suitable combinationand location. Still further, various functions described herein as beingperformed by one or more entities may be carried out by hardware,firmware and/or software logic. For instance, various functions may becarried out by a processor executing a set of machine languageinstructions stored in memory.

As shown, the access network may include a plurality of base stations104, 105. Each base station of the access network may function totransmit and receive RF radiation 102, 103 at one or more carrierfrequencies, and the RF radiation may then provide one or more airinterfaces over which the wireless device 101 may communicate with thebase stations 104, 105. The user 101 may use the wireless device toreceive data traffic, such as one or more multimedia files, data files,pictures, video files, or voice mails, etc. The wireless device 101 mayinclude applications such as web email, email applications, upload andftp applications, MMS applications, or file sharing applications. Inanother example embodiment, the wireless device 101 may automaticallysend traffic to another wireless device or a server in the networkwithout direct involvement of a user. For example, consider a wirelesscamera with automatic upload feature, or a video camera uploading videosto the remote server, or a personal computer equipped with anapplication transmitting traffic to a remote server.

Each of the one or more base stations 104, 105 may define acorresponding wireless coverage area. The RF radiation 102, 103 of thebase stations may carry communications between the Wireless CellularNetwork/Internet Network and access device 101 according to any of avariety of protocols. For example, RF radiation 102, 103 may carrycommunications according to WiMAX (e.g., IEEE 802.16), LTE,LTE-Advanced, microwave, satellite, MMDS, Wi-Fi (e.g., IEEE 802.11),Bluetooth, infrared, and other protocols now known or later developed.The communication between the wireless device 101 and other wirelessdevices or a server may be enabled by any networking and transporttechnology for example TCP/IP, RTP, RTCP, HTTP or any other networkingprotocol.

In an example embodiment, an LTE or LTE-Advanced network includes manybase stations 104, 105, providing a user plane (PDCP/RLC/MAC/PHY) andcontrol plane (RRC) protocol terminations towards the wireless device101. The base stations may be interconnected with each other by means ofthe X2 interface 110. In another embodiment, X2 interface may beprovided by interfaces 112, 113 and gateway 117. Any other digitalmedium may be used to enable X2 interface. The base stations may also beconnected by means of the S1 interface to the EPC (Evolved Packet Core),more specifically to the MME (Mobility Management Entity) 122 by meansof the S1-MME interface and to the Serving Gateway (S-GW) 118 by meansof the S1-U interface. The S1 interface may support a many-to-manyrelation between MMEs/Serving Gateways and base stations. An S-GW may beconnected to one or more PDN gateways. MME, S-GW, and P-GW arefunctional nodes and may or may not be combined to physical nodes. Forexample, S-GW and P-GW may be combined in a physical node, or MME andS-GW may be combined in a physical node, or MME, P-GW, and S-GW may beall combined in a physical node.

A base station may include many sectors for example 2, 3, 4, or 6sectors. A base station may include many cells. A cell may becategorized as a primary cell or secondary cell. When carrieraggregation is configured, a wireless device may have one RRC connectionwith the network. At RRC connectionestablishment/re-establishment/handover, one serving cell provides theNAS (non-access stratum) mobility information (e.g. TAI), and at RRCconnection re-establishment/handover, one serving cell provides thesecurity input. This cell is referred to as the Primary Cell (PCell). Inthe downlink, the carrier corresponding to the PCell is the DownlinkPrimary Component Carrier (DL PCC) while in the uplink it is the UplinkPrimary Component Carrier (UL PCC). Depending on wireless devicecapabilities, Secondary Cells (SCells) may be configured to formtogether with the PCell a set of serving cells. In the downlink, thecarrier corresponding to an SCell is a Downlink Secondary ComponentCarrier (DL SCC) while in the uplink it is an Uplink Secondary ComponentCarrier (UL SCC). An SCell may or may not have an uplink carrier.

Packet routing and transfer functions are performed in a cellularnetwork. A route may be an ordered list of nodes used for the transferof packets within and between the PLMN(s). Each route may include of theoriginating node, zero or more relay nodes and the destination node.Routing is the process of determining and employing, in accordance witha set of rules, the route for transmission of a message within andbetween the PLMN(s). The EPS (Evolved Packet System) may be an IPnetwork and may use routing and transport mechanisms of the underlyingIP network. The Maximum Transfer Unit (MTU) size may also applicable toEPS. The IP header compression function may be implemented to reduce theuse of radio capacity by IP header compression mechanisms. The packetscreening function may provide the network with the capability to checkthat the wireless device is employing the proper IPv4-Address and/orIPv6-Prefix that is assigned to the UE (wireless device).

The mobility management functions are used to keep track of the currentlocation of a UE. Radio resource management functions are concerned withthe allocation and maintenance of radio communication paths, and may beperformed by the radio access network. The RRM strategy in E-UTRAN(evolved universal terrestrial radio access network) may be based onuser specific information. To support radio resource management inE-UTRAN the MME (mobility management entity) may provide some of theradio resource management related parameters to an eNodeB across S1interface. S1 interface is the interface between an eNodeB and an MME.

An EPS network includes E-UTRAN. E-UTRAN functions may include at leastone of the following functions: Header compression and user planeciphering; MME selection when no routing to an MME can be determinedfrom the information provided by the UE; UL bearer level rateenforcement based on UE-AMBR and MBR via means of uplink scheduling(e.g. by limiting the amount of UL resources granted per UE over time);DL bearer level rate enforcement based on UE-AMBR; UL and DL bearerlevel admission control; Transport level packet marking in the uplink,e.g. setting the DiffServ Code Point, based on the QCI of the associatedEPS bearer; ECN-based congestion control.

EPS may also include at least one MME. MME functions include at leastone or many of the following: NAS signalling; NAS signalling security;Inter CN node signalling for mobility between 3GPP access networks(terminating S3); UE Reachability in ECM-IDLE state (including controland execution of paging retransmission); Tracking Area list management;Mapping from UE location (e.g. TAI) to time zone, and signalling a UEtime zone change associated with mobility, PDN GW and Serving GWselection; MME selection for handovers with MME change; SGSN selectionfor handovers to 2G or 3G 3GPP access networks; Roaming (S6a towardshome HSS); Authentication; Authorization; Bearer management functionsincluding dedicated bearer establishment; Lawful Interception ofsignalling traffic; Warning message transfer function (includingselection of appropriate eNodeB); UE Reachability procedures; SupportRelaying function (RN Attach/Detach). The Serving GW and the MME may beimplemented in one physical node or separated physical nodes.

EPS may include two logical Gateways including Serving GW (S-GW) and PDNGW (P-GW). The PDN GW and the Serving GW may be implemented in onephysical node or separated physical nodes.

The Serving GW is the gateway which may terminate the interface towardsE-UTRAN. For each UE associated with the EPS, at a given point of time,there may be a Serving GW. The functions of the Serving GW, for both theGTP-based and the PMIP-based S5/S8, may include at least one of thefollowing: the local Mobility Anchor point for inter-eNodeB handover;sending of one or more “end marker” to the source eNodeB, source SGSN orsource RNC immediately after switching the path during inter-eNodeB andinter-RAT handover, especially to assist the reordering function ineNodeB; Mobility anchoring for inter-3GPP mobility (terminating S4 andrelaying the traffic between 2G/3G system and PDN GW); ECM-IDLE modedownlink packet buffering and initiation of network triggered servicerequest procedure; Lawful Interception; Packet routing and forwarding;Transport level packet marking in the uplink and the downlink, e.g.setting the DiffServ Code Point, based on the QCI of the associated EPSbearer; Accounting for inter-operator charging. For GTP-based S5/S8, theServing GW generates accounting data per UE and bearer.

The PDN GW is the gateway which may terminate the SGi interface towardsthe PDN. If a UE is accessing multiple PDNs, there may be more than onePDN GW for that UE, however a mix of S5/S8 connectivity and Gn/Gpconnectivity is not supported for that UE simultaneously. PDN GWfunctions include for both the GTP-based and the PMIP-based S5/S8 atleast one of the following: Per-user based packet filtering (by e.g.deep packet inspection), Lawful Interception; UE IP address allocation;Transport level packet marking in the uplink and downlink, e.g. settingthe DiffServ Code Point, based on the QCI of the associated EPS bearer;Accounting for inter-operator charging; UL and DL service level charging(e.g. based on SDFs defined by the PCRF, or based on deep packetinspection defined by local policy); Interfacing OFCS through accordingto charging principles and through reference points; UL and DL servicelevel gating control; UL and DL service level rate enforcement (e.g. byrate policing/shaping per SDF); UL and DL rate enforcement based onAPN-AMBR (e.g. by rate policing/shaping per aggregate of traffic of allSDFs of the same APN that are associated with Non-GBR QCIs); DL rateenforcement based on the accumulated MBRs of the aggregate of SDFs withthe same GBR QCI (e.g. by rate policing/shaping); DHCPv4 (server andclient) and DHCPv6 (client and server) functions; The network does notsupport PPP bearer type in this version of the specification.Pre-Release 8 PPP functionality of a GGSN may be implemented in the PDNGW; packet screening. Additionally the PDN GW may include at least oneof the following functions for the GTP-based S5/S8: UL and DL bearerbinding; UL bearer binding verification; Accounting per UE and bearer.

The PDN GW selection function allocates a PDN GW that may provide thePDN connectivity for the 3GPP access. The function may use subscriberinformation provided by the HSS and possibly additional criteria. Thecriteria for PDN GW selection may include load balancing between PDNGWs. When the PDN GW IP addresses returned from a DNS server includeWeight Factors, the MME may use it if load balancing is required. TheWeight Factor may be set according to the capacity of a PDN GW noderelative to other PDN GW nodes serving the same APN.

The PDN subscription contexts provided by the HSS may comprise at leastone of: a) the identity of a PDN GW and an APN (PDN subscriptioncontexts with subscribed PDN GW address are not used when there isinteroperation with pre Rel-8 2G/3G SGSN), b) an APN and an indicationfor this APN whether the allocation of a PDN GW from the visited PLMN isallowed or whether a PDN GW from the home PLMN may be allocated.Optionally an identity of a PDN GW may be contained for handover withnon-3GPP accesses, c) optionally for an APN, an indication of whetherSIPTO (Selected IP Traffic Offload) is allowed or prohibited for thisAPN.

In the case of static address allocation, a static PDN GW may beselected by either having the APN configured to map to a given PDN GW,or the PDN GW identity provided by the HSS indicates the static PDN GW.The HSS may indicate which of the PDN subscription contexts is thedefault one for the UE. To establish connectivity with a PDN when the UEis already connected to one or more PDNs, the UE may provide therequested APN for the PDN GW selection function.

If one of the PDN subscription contexts provided by the HSS contains awild card APN, a PDN connection with dynamic address allocation may beestablished towards any APN requested by the UE. An indication thatSIPTO is allowed or prohibited for the wild card APN may allow orprohibit SIPTO for any APN that is not present in the subscription data.

If the HSS provides the identity of a statically allocated PDN GW, orthe HSS provides the identity of a dynamically allocated PDN GW and theRequest Type indicates “Handover”, no further PDN GW selectionfunctionality may be performed. If the HSS provides the identity of adynamically allocated PDN GW, the HSS may provide information thatidentifies the PLMN in which the PDN GW is located.

If the HSS provides the identity of a dynamically allocated PDN GW andthe Request Type indicates “initial Request”, either the provided PDN GWmay be used or a new PDN GW may be selected. When a PDN connection foran APN with SIPTO permissions is requested, the PDN GW selectionfunction may ensure the selection of a PDN GW that is appropriate forthe UE's location. The PDN GW identity refers to a specific PDN GW. Ifthe PDN GW identity includes the IP address of the PDN GW, that IPaddress may be used as the PDN GW IP address; otherwise the PDN GWidentity may include an FQDN which is used to derive the PDN GW IPaddress by employing Domain Name Service function, taking into accountthe protocol type on S5/S8 (PMIP or GTP).

If the HSS provides a PDN subscription context that allows forallocation of a PDN GW from the visited PLMN for this APN, the PDN GWselection function may derive a PDN GW identity from the visited PLMN.If a visited PDN GW identity cannot be derived, or if the subscriptiondoes not allow for allocation of a PDN GW from the visited PLMN, thenthe APN may be used to derive a PDN GW identity from the HPLMN. The PDNGW identity is derived from the APN, subscription data and additionalinformation by employing the Domain Name Service function. If the PDN GWidentity is a logical name instead of an IP address, the PDN GW addressis derived from the PDN GW identity, protocol type on S5/S8 (PMIP orGTP) by employing the Domain Name Service function. The S8 protocol type(PMIP or GTP) may be configured per HPLMN in MME/SGSN.

In order to select the appropriate PDN GW for SIPTO service, the PDN GWselection function uses the TAI (Tracking Area Identity), the servingeNodeB identifier, or TAI together with serving eNodeB identifierdepending on the operator's deployment during the DNS interrogation tofind the PDN GW identity. In roaming scenario PDN GW selection for SIPTOmay be possible when a PDN GW in the visited PLMN is selected. Thereforein a roaming scenario with home routed traffic, PDN GW selection forSIPTO may not be performed.

The PDN GW domain name may be constructed and resolved by a method,which takes into account any value received in the APN-OI Replacementfield for home routed traffic. If the Domain Name Service functionprovides a list of PDN GW addresses, one PDN GW address may be selectedfrom this list. If the selected PDN GW cannot be used, e.g. due to anerror, then another PDN GW may be selected from the list. The specificinteraction between the MME/SGSN and the Domain Name Service functionmay include functionality to allow for the retrieval or provision ofadditional information regarding the PDN GW capabilities (e.g. whetherthe PDN GW supports PMIP-based or GTP-based S5/S8, or both).

If the UE provides an APN for a PDN, this APN may then be used to derivethe PDN GW identity as specified for the case of HSS provided APN if oneof the subscription contexts allows for this APN. If there is anexisting PDN connection to the same APN used to derive the PDN GWaddress, the same PDN GW may be be selected. As part of PDN GWselection, an IP address of the assigned PDN GW may be provided to theUE for use with host based mobility, if the PDN GW supports host-basedmobility for inter-access mobility towards accesses where host-basedmobility may be used. If a UE explicitly requests the address of the PDNGW and the PDN GW supports host based mobility then the PDN GW addressmay be returned to the UE.

The Serving GW selection function may select an available Serving GW toserve a UE. The selection bases on network topology, i.e. the selectedServing GW serves the UE's location and for overlapping Serving GWservice areas, the selection may prefer Serving GWs with service areasthat reduce the probability of changing the Serving GW. When SIPTO isallowed then it is also considered as a criterion for Serving GWselection, e.g. when the first PDN connection is requested. Othercriteria for Serving GW selection may include load balancing betweenServing GWs. When the Serving GW IP addresses returned from the DNSserver include Weight Factors, the MME may use it if load balancing isrequired. The Weight Factor is typically set according to the capacityof a Serving GW node relative to other Serving GW nodes serving the sameTracking area.

If a subscriber of a GTP network roams into a PMIP network, the PDN GWsselected for local breakout support the PMIP protocol, while PDN GWs forhome routed traffic use GTP. This means the Serving GW selected for suchsubscribers may need to support both GTP and PMIP, so that it ispossible to set up both local breakout and home routed sessions forthese subscribers. For a Serving GW supporting both GTP and PMIP, theMME/SGSN may indicate the Serving GW which protocol may be used overS5/S8 interface. The MME/SGSN is configured with the S8 variant(s) on aper HPLMN granularity.

If a subscriber of a GTP network roams into a PMIP network, the PDN GWsselected for local breakout may support GTP or the subscriber may not beallowed to use PDN GWs of the visited network. In both cases a GTP basedServing GW may be selected. These cases are considered as roamingbetween GTP based operators.

If combined Serving and PDN GWs are configured in the network theServing GW Selection Function preferably derives a Serving GW that isalso a PDN GW for the UE.

The Domain Name Service function may be used to resolve a DNS stringinto a list of possible Serving GW addresses which serve the UE'slocation. The specific interaction between the MME/SGSN and the DomainName Service function may include functionality to allow for theretrieval or provision of additional information regarding the ServingGW capabilities (e.g. whether the Serving GW supports PMIP-based orGTP-based S5/S8, or both). The details of the selection areimplementation specific.

The MME selection function selects an available MME for serving a UE.The selection may be based on network topology, i.e. the selected MMEserves the UE's location and for overlapping MME service areas, theselection may prefer MMEs with service areas that reduce the probabilityof changing the MME. When a MME/SGSN selects a target MME, the selectionfunction performs a simple load balancing between the possible targetMMEs.

When an eNodeB selects an MME, the eNodeB may use a selection functionwhich distinguishes if the GUMMEI is mapped from P-TMSI/RAI or is anative GUMMEI. The indication of mapped or native GUMMEI may besignalled by the UE to the eNodeB as an explicit indication. The eNodeBmay differentiate between a GUMMEI mapped from P-TMSI/RAI and a nativeGUMMEI based on the indication signalled by the UE. Alternatively, thedifferentiation between a GUMMEI mapped from P-TMSI/RAI and a nativeGUMMEI may be performed based on the value of most significant bit ofthe MME Group ID, for PLMNs that deploy such mechanism. In this case, ifthe MSB is set to “0” then the GUMMEI is mapped from P-TMSI/RAI and ifMSB is set to “1”, the GUMMEI is a native one. Alternatively the eNodeBmay make the selection of MME based on the GUMMEI without distinguishingon mapped or native. When an eNodeB selects an MME, the selection mayachieve load balancing.

An eNodeB may connect to several MMEs. This may imply that an eNodeB maybe able to determine which of the MMEs, covering the area where an UE islocated, may receive the signalling sent from a UE. To avoid unnecessarysignalling in the core network, a UE that has attached to one MME shouldgenerally continue to be served by this MME as long as the UE is in theradio coverage of the pool area to which the MME is associated. Theconcept of pool area is a RAN based definition that comprises one ormore TA(s) that, from a RAN perspective, are served by a certain groupof MMEs. This does not exclude that one or more of the MMEs in thisgroup serve TAs outside the pool area. This group of MMEs may alsoreferred to as an MME pool.

To enable the eNodeB to determine which MME to select when forwardingmessages from an UE, this functionality may define a routing mechanism(and other related mechanism). A routing mechanism (and other relatedmechanism) is defined for the MMEs. The routing mechanism is required tofind the correct old MME (from the multiple MMEs that are associatedwith a pool area). When a UE roams out of the pool area and into thearea of one or more MMEs that do not know about the internal structureof the pool area where the UE roamed from, the new MME will send theIdentification Request message or the Context Request message to the oldMME employing the GUTI. The routing mechanism in both the MMEs and theeNodeB utilises the fact that every MME that serves a pool area musthave its own unique value range of the GUTI parameter within the poolarea.

X2 interface may be used for handover signalling and data forwardingbetween two eNodeBs. X2 interface connects two eNodeBs. X2 interface maybe established between two eNodeBs in two cell sites. X2 interface maybe established employing cell site gateways. An LSP may be establishedfrom a cell site gateway in a wireless site to another cell site gatewayin another network site. Upon handover from a source eNodeB to adestination eNodeB (eNB), the source eNB may forward in order to thetarget eNB all downlink PDCP SDUs with their SN (sequence number) thathave not been acknowledged by the UE. In addition, the source eNB mayalso forward without a PDCP SN fresh data arriving over S1 to the targeteNB. The target eNB may not have to wait for the completion offorwarding from the source eNB before it begins transmitting packets tothe UE. This may be enabled packet transfer employing label switchedpath established between two cell site gateways. A cell site gateway mayestablish an LSP to another cell site gateway to carry X2 signalling anddata traffic. The cell site gateway may also establish an LSP to packetnetwork gateway to carry S1 signaling and data traffic.

The source eNB may discard any remaining downlink RLC PDUs.Correspondingly, the source eNB does not forward the downlink RLCcontext to the target eNB. The source eNB may not need to abort on goingRLC (radio link control) transmissions with the UE as it starts dataforwarding to the target eNB.

Upon handover, the source eNB may forward to the Serving Gateway theuplink PDCP SDUs successfully received in-sequence until the sending ofthe Status Transfer message to the target eNB. Then at that point oftime the source eNB may stop delivering uplink PDCP SDUs to the S-GW andmay discard any remaining uplink RLC PDUs. Correspondingly, the sourceeNB may not forward the uplink RLC context to the target eNB.

Then the source eNB may either: a) discard the uplink PDCP SDUs receivedout of sequence if the source eNB has not accepted the request from thetarget eNB for uplink forwarding or if the target eNB has not requesteduplink forwarding for the bearer during the Handover Preparationprocedure, or b) forward to the target eNB the uplink PDCP SDUs receivedout of sequence if the source eNB has accepted the request from thetarget eNB for uplink forwarding for the bearer during the HandoverPreparation procedure.

For normal HO in-sequence delivery of upper layer PDUs during handovermay be based on a continuous PDCP SN and is provided by the in-orderdelivery and duplicate elimination function at the PDCP layer: a) in thedownlink, the “in-order delivery and duplicate elimination” function atthe UE PDCP layer may maintain in-sequence delivery of downlink PDCPSDUs; b) in the uplink, the “in-order delivery and duplicateelimination” function at the target eNB PDCP layer may maintainin-sequence delivery of uplink PDCP SDUs.

After a normal handover, when the UE receives a PDCP SDU from the targeteNB, it may deliver it to higher layer together with all PDCP SDUs withlower SNs regardless of possible gaps. For handovers involving FullConfiguration, the source eNB behavior is unchanged from the descriptionabove. The target eNB may not send PDCP SDUs for which delivery wasattempted by the source eNB. The target eNB identifies these by thepresence of the PDCP SN in the forwarded GTP-U packet and may discardthem. After a Full Configuration handover, the UE may deliver receivedPDCP SDU from the source cell to the higher layer regardless of possiblegaps. UE may discard uplink PDCP SDUs for which transmission wasattempted and retransmission of these over the target cell is notpossible.

Transport network may provide a reliable aggregation and transportinfrastructure for any client traffic type. With the growth ofpacket-based services, operators may transform their networkinfrastructures while looking at reducing capital and operationalexpenditures. Multi-protocol label switching or transport profile ofmulti-protocol label switching may be implemented.

MPLS-TP may provide connection-oriented transport for packet and TDMservices over optical networks leveraging the widely deployed MPLStechnology. Generalized MPLS (GMPLS) is a generalization of the MPLScontrol plane to develop a dynamic control plane that may be applied topacket switched and optical networks. The GMPLS control plane maysupport connection management functions as well as protection andrestoration techniques and thus providing network survivability acrossnetworks comprising routers, MPLS-TP LSRs, optical ADMs, cross connects,and WDM devices. MPLS-TP may utilize the distributed control plane toenable fast, dynamic and reliable service provisioning in multi-vendorand multi-domain environments employing standardized protocols thatensure interoperability.

A control plane is based on a combination of the MPLS control plane forpseudowires and the GMPLS control plane for MPLS-TP LSPs may beconsidered. A distributed MPLS-TP control plane may provide thefollowing basic functions: Signaling, Routing, Traffic engineering andconstraint-based path computation. Moreover, the MPLS-TP control planemay be capable of performing fast restoration in the event of networkfailures. The MPLS-TP control plane may provide features to ensure itsown survivability and to enable it to recover gracefully from failuresand degradations. These include graceful restart and hot redundantconfigurations. The MPLS-TP control plane is as much as possibledecoupled from the MPLS-TP data plane such that failures in the controlplane do not impact the data plane and vice versa. MPLS-TP is a set ofMPLS protocols that are being defined in IETF. It is a simplifiedversion of MPLS for transport networks with some of the MPLS functionsturned off, such as Penultimate Hop Popping (PHP), Label-Switched Paths(LSPs) merge, and Equal Cost Multi Path (ECMP). MPLS-TP does not requireMPLS control plane capabilities and enables the management plane to setup LSPs manually. Its OAM may operate without any IP layerfunctionalities.

The essential features of MPLS-TP are MPLS forwarding plane withrestrictions, PWE3 Pseudowire architecture, Control Plane: static ordynamic Generalized MPLS (G-MPLS), Enhanced OAM functionality, OAMmonitors and drives protection switching, Use of Generic AssociatedChannel (G-ACh) to support fault, configuration, accounting,performance, security (FCAPS) functions, and Multicasting. IP/MPLS maybe scalable and can be deployed end-to-end to accommodate the needs ofany network size.

In some cases, a service provider may not want to deploy a dynamiccontrol plane based on IP protocols in some areas of the network. Forexample, the multiplication of Pseudowires (PWs) for some applicationssuch as mobile backhaul may require IP addresses for the PWs. A staticconfiguration of PWs may be considered. In addition, protection based onMPLS-Traffic Engineering (TE) may not be manageable in a situation wherethe complexity associated with a TE/Fast Reroute (FRR) setup to protectthousands of nodes/paths may be a challenge. MPLS-TP solution may allowstatic provisioning in the MPLS-TP domain. This approach may ease thetransition from legacy transport technologies to an MPLS infrastructure.MPLS-TP and IP/MPLS may be integrated so that LSPs and PWs may beprovisioned and managed smoothly, end-to-end.

Within the context of MPLS-TP, the control plane is the mechanism usedto set up an LSP automatically across a packet-switched network domain.The use of a control plane protocol may be optional in MPLS-TP. Someoperators may prefer to configure the LSPs and PWs employing a NetworkManagement System in the same way that it may be used to provision aSONET network. In this case, no IP or routing protocol may be used. Onthe other hand, it is possible to use a dynamic control plane withMPLS-TP so that LSPs and PWs are set up by the network employingGeneralized (G)-MPLS and Targeted Label Distribution Protocol (T-LDP)respectively. G-MPLS is based on the TE extensions to MPLS (MPLS-TE). Itmay also be used to set up the OAM function and define recoverymechanisms. T-LDP is part of the PW architecture and is widely usedtoday to signal PWs and their status.

MPLS may be designed to carry Layer 3 IP traffic by establishingIP-based paths and associating these paths with arbitrarily assignedlabels. These labels may either be configured explicitly by a networkadministrator or dynamically assigned by a protocol such as the LabelDistribution Protocol (LDP) or Resource Reservation Protocol (RSVP).GMPLS may carry various types of Layer 1 through Layer 3 traffic. GMPLSlabels and LSPs may be processed at four levels. The levels, forexample, may be Fiber-Switched Capable (FSC), Lambda-Switched Capable(LSC), Time-Division Multiplexing Capable (TDM), and Packet-SwitchedCapable (PSC).

LSPs may start and end on links with the same switching capability. Tosend an LSP, a label-switched device may communicate with another deviceat the same layer of the Open System Interconnection (OSI) model. Thus,routers may set up PSC LSPs with other routers at Layer 3, and SONET/SDHadd/drop multiplexers (ADMs) may establish TDM LSPs with other ADMs atLayer 1. A router PSC LSP may be carried over a TDM LSP, a TDM LSP maybe carried over a wavelength LSC LSP, and so on.

This extension of the MPLS protocol may expand the number of devicesthat may participate in label switching. Lower layer devices, such asEthernet switches, optical cross-connects (OXCs) and SONET/SDH ADMs, maynow participate in GMPLS signaling and set up paths to transfer data.Additionally, routers may participate in signaling optical paths acrossa transport network. GMPLS labeling may be more flexible than MPLS. AGMPLS label may represent a TDM time slot, a Dense Wavelength DivisionMultiplexing (DWDM) wavelength (also known as a lambda), or a physicalport number. The labels may be derived from physical components of thenetwork devices, such as interfaces.

To enable multilayer LSPs, GMPLS may use the following mechanisms: a)Separation of the control channel from the data channel—A new protocolcalled Link Management Protocol (LMP) may be used to define and manageboth control channels and data channels between GMPLS peers. Messagesfor GMPLS LSP setup are sent from one device to a peer device over anout-of-band control channel. Once the LSP setup is complete and the pathis provisioned, the data channel may be established and may be used tocarry traffic. In GMPLS, the control channel is always separate from thedata channel. b) RSVP-TE extensions for GMPLS—RSVP-TE was designed tosignal the setup of packet LSPs. The protocol has been extended torequest path setup for non-packet LSPs that use wavelengths, time slots,and fibers as potential labels. C) OSPF extensions for GMPLS—OSPF wasdesigned to route packets to physical and logical interfaces related toa PIC. This protocol has been extended to route packets to virtual peerinterfaces defined in an LMP configuration. D) Bidirectional LSPs—Unlikeunidirectional LSP paths found in the standard, packet-based version ofMPLS, data may travel both ways between GMPLS devices over a single LSPpath.

GMPLS is intended to bridge the gap between the traditional transportinfrastructure and the IP layer. GMPLS may be designed to enablemultivendor interoperability and multilayer functionality. Routers orswitches may be able to make dynamic requests for extra bandwidth ondemand from the optical network. Consequently, service providers mayenvision GMPLS as a means to set up optical circuits or label switchedpaths and services dynamically instead of manually.

In the example embodiments, cell site gateway may implement MPLS,MPLS-TP, or MPLS-TP along with GMPLS control plane. All options may bepossible, and a service operator may implement one or many of theseprotocols. If MPLS is deployed, then the cell site gateway may usein-band signaling to establish a label switched path. For MPLS-TP,static or dynamic configuration option and LSP set up processes may beused. When MPLS-TP with GMPLS control plane is implemented, then GMPLScontrol plane may be used to implement network signaling and establishan LSP. When labels are configured in a network nodes and cell sitegateway employing static or dynamic methods, then an LSP may be set up.Cell site gateway and network nodes may insert or remove labels onpackets and forward packets along an LSP. Pseudo wires may beestablished to carry multiple types of traffic along LSPs. Additionallabels may be implemented for example for identifying pseudo-wires. LSPsmay be established between cell site gateway and packet network gateway,or LSPs may be established between cell site gateway directly orindirectly through packet network gateway or other networkgateways/nodes.

FIG. 1 is a simplified block diagram depicting a communication systemfor transmitting and receiving packets to and from a wireless device 101according to an exemplary embodiment. FIG. 2 is a diagram depicting afirst example of a wireless network site according to an exemplaryembodiment. In an example embodiment, a wireless network site 121, 122may comprise a first base station 104, 105, 201 and a cell site gateway106, 107, 202. The first base station 201, 102, 103 may communicateemploying a wireless technology with at least one wireless device 101via air interface 102, 103. The wireless technology may use a protocollayer architecture comprising a physical layer. The physical layer maysupport simultaneous transmission employing a plurality of antennae ineach sector of the first base station. For example, antennae 206 and 205are in sector one, antennae 207 and 208 are in sector two, and antennae209 and 210 are in sector three. As an example, in sector two antennae207 and 208 may simultaneously transmit signals 212 and 213 to wirelessdevice 214. Multiple antennae may be installed in a single antennapackaging or multiple antenna packaging.

The first base station 104, 105, 201 may communicate with a cellularnetwork gateway 118 through the cell site gateway 106, 107, 202. Thecell site gateway 106, 107, 202 may comprise a first interface 108, 109,203, a second interface 112, 113, 204, a third interface 114, 111, and alabel forwarding layer. The first interface 108, 109, 203 may beconnected to the first base station. The second interface 108, 109, 203may be connected to a packet network gateway 117, 211. The thirdinterface 114, 111 may be connected to a signaling peer 119 to exchangecontrol plane information to program a forwarding layer. The signalingpeer may reside in the control plane network 116. The control planeinformation may comprise at least one first label and at least onesecond label value. The at least one first label value may be used fortransmitting a first plurality of packets to the first base station. Theat least one second label value may be used for transmitting a secondplurality of packets to the packet network gateway. The signaling peerexchanges 119 the control plane information with the packet networkgateway 117, 211 via interface 115. The label forwarding layer maytransmit the second plurality of packets to the packet network gatewayemploying the second interface. The label forwarding layer may receivethe first plurality of packets from the packet network gateway employingthe second interface. The label forwarding layer may attach at least oneof the at least one second label to the second plurality of packets. Thelabel forwarding layer may remove at least one of the at least one firstlabel from the first plurality of packets.

In an example implementation, the third interface may be integrated inthe second interface. MPLS may be used as the control plane. Signalingprotocols such as RSVP, LDP, or other signaling methods may be used toestablish a label switched path between cell site gateway and packetnetwork gateway to transfer S1 traffic and signaling, and label switchedpath may also be established between cell site gateways for exchange oftraffic and signaling between base stations. Then signaling traffic maybe exchanged on the second interface. Label switched paths may also beestablished statically employing a management platform to simplifynetwork operation. In these implementations, label switching and labelforwarding is used for packet transfer along a label switched path.

In another example embodiment, a wireless network site may comprise afirst base station and a cell site gateway. The first base station maycommunicate employing a wireless technology with at least one wirelessdevice. The wireless technology may use a protocol layer architecturecomprising a physical layer supporting simultaneous transmissionemploying a plurality of antennae in each sector of the first basestation. The first base station may communicate with at least one basestation through a cell site gateway. The first base station maycommunicate with a cellular network gateway through the cell sitegateway. The cell site gateway may comprise a first interface, a secondinterface, and a label forwarding layer. The first interface may beconnected to the base station. The second interface may be connected toa packet network gateway. The third interface may be connected to asignaling peer to exchange control plane information to program aforwarding layer.

The control plane information comprise at least one first label valuefor transmitting a first plurality of packets to the first base station,at least one second label value for transmitting a second plurality ofpackets to the packet network gateway, and at least one parametercharacterizing the second interface. The signaling peer may exchange thecontrol plane information with the packet network gateway. The labelforwarding layer may transmit the second plurality of packets to thepacket network gateway employing the second interface. The labelforwarding layer may receive the first plurality of packets from thepacket network gateway employing the second interface. The labelforwarding layer may attach at least one of the at least one secondlabel to the second plurality of packets. The label forwarding layer mayremove at least one of the at least one first label from the firstplurality of packets.

The packet network gateway 117 is directly or indirectly connected tothe cellular network gateway 118. The wireless network cell site maycomprise at least one additional second base station connected to thecell site gateway. The wireless network cell site may comprise aplurality of base stations for example an LTE base station and an HSPAbase station. The base stations in the cell site may receive andtransmit packets to the cell site gateway.

The second plurality of packets may be transmitted to the packet networkgateway 118 via at least one intermediate network node. The at least onefirst label and the at least one second label may comprise a labelvalue, a class of service, and/or bottom of label stack flag. The cellsite gateway 202 may comprise the second interface 204 link information.The second interface 204 link information may comprise of at leastfollowing information: link bandwidth information, shared risk linkinformation, link protection type, and switching capability.

The signaling peer 119 is attached to the control plane for exchangingthe control plane information with the cell site gateway 106, 107. Thelabel forwarding layer may further comprise swapping label on a thirdplurality of packets. The cell site gateway may comprise of a pathcomputation engine. The cell site gateway may exchange the control planeinformation employing RSVP-TE via the third interface. The cell sitegateway may exchange the control plane information employing MPLS-TP.The cell site gateway may exchange the control plane informationemploying a label distribution mechanism via the third interface. Thecell site gateway may comprise of routing functionality supporting alink state routing protocol. The link state routing protocol may be oneof OSPF and IS-IS. The wireless technology may be LTE or LTE-Advancedtechnology. The wireless technology may be one of the following: 802.11family of technologies, Bluetooth technology, and WiMAX technology.

The cellular network gateway may be an LTE Serving Gateway. The cellularnetwork gateway may be connected to an LTE Serving Gateway. The cellularnetwork gateway and the packet network gateway may be co-located or maybe physically in the same network cabinet. The first base station maycomprise a plurality of cells. The first base station may comprise aplurality of antennae. The first interface may be an Ethernet interface.The first base station may communicate with a cellular network gatewayemploying a backhaul interface. The cell site gateway may transmit thefirst plurality of packets to the first base station via the firstinterface. The cell site gateway may receive the second plurality ofpackets from the first base station via the first interface. The cellsite gateway processes packet headers of the first plurality of packetsand the second plurality of packets. The cell site gateway modifiespacket headers of the first plurality of packets and the secondplurality of packets. The first base station may process packet headersof the first plurality of packets and the second plurality of packets.The first base station may modify packet headers of the first pluralityof packets and the second plurality of packets. Packets travel from thecellular network gateway to the wireless device and from the wirelessdevice to cellular network gateway while passing through base station,cell site gateway, and packet network gateway. Each node may processpacket headers and may update packet headers. Some of the nodes may alsofragment or concatenate packets depending on the underlying layer 1 andlayer 2 technologies.

The first base station may forward at least one of the first pluralitypackets received from the cell site gateway to one of the at least onebase station during the handover procedure. The first base station mayforward at least one of the first plurality of packets received from thecell site gateway to the cell site gateway during the handoverprocedure. The first base station may transmit at least one of the firstplurality of packets to the at least one wireless device. The first basestation may receive at least one of the second plurality of packets fromthe at least one wireless device. The first base station may comprise aplurality of sectors, and each sector in the plurality of sectors maycomprise a plurality of antennas. The first base station may transmit atleast one of the first plurality of packets to one of the at least onewireless device employing a plurality of antennas belonging to at leasttwo sectors in the plurality of sectors. The first base station mayreceive at least one of the second plurality of packets from one of theat least one wireless device employing a plurality of antennas belongingto at least two sectors in the plurality of sectors. The cell sitegateway communicates with the at least one base station. The cell sitegateway may transmit a plurality of packets received from the first basestation to the at least one base station. The cell site gateway mayfurther comprise an interface for management functions. The cell sitegateway may use the management interface for managing the device forprovisioning and maintenance. The cell site gateway may use themanagement interface for connecting to the wireless network managementnetwork for operations, management and administration.

FIG. 3 is a diagram depicting a second example of a wireless networksite according to an exemplary embodiment. In an example embodiment, thefirst base station 301 and the cell site gateway 302 may be located inthe same physical location. The first base station 301 and the cell sitegateway 302 may be interconnected via an internal interface 303. Thecell site gateway 302 may be connected to the packet network gateway 305via interface 304. In another example embodiment the first base stationand the cell site gateway may be located in different physicallocations. The different physical locations are connected to each othervia digital links. For example, the base station may be located at thecell site, and the cell site gateway may be located in a POP (point ofpresence) or maybe located in an aggregation point. The cell sitegateway may provide backhaul connection to a plurality of base stationslocated in a plurality of cell sites.

FIG. 4 is a simplified diagram depicting connections between a cell sitegateway and a cellular network gateway according to an exemplaryembodiment. In an example embodiment, the signaling peer may be adjacentwith the cell site gateway in data plane. In an example embodiment, thesignaling peer 405 may reside in in the packet network gateway 402. Thesignaling peer may exchange the control plane information with thepacket network gateway via an internal interface. The signalinginterface 404 may connect the cell site gateway 401 to the signalingpeer 405 in the packet network gateway 402. The packet network gateway402 may be connected to cell site gateway 401 via interface 403. Thesignaling peer and/or the cell site gateway may support out-band MPLSsignaling for label distribution or label switched path set up. In thecase of out-band signaling, the interface 403 and 404 may be twoseparate physical interfaces, or they may be two separate signals on thesame physical interface. For example, two different wavelengths in anoptical interface, or packets transmitted in different formats on thesame frequency. The signaling peer may also support in-band MPLSsignaling for label distribution. In an example embodiment, interfaces403 and 404 may be two different logical interfaces, e.g. one for dataand the other one for signaling, and may transferred on the samephysical port and physical link. There may be at least two logical portson a physical port and enable interface 403 and 404. In another exampleembodiment, the signaling peer may not adjacent with the cell sitegateway in data plane. The signaling peer may be a standalone node or afunctional node integrated into another physical node.

FIG. 5 is a block diagram of a base station 501 and a gateway 506according to an exemplary embodiment. A communication network includesat least one base station 501 and at least one gateway 506. The basestation 501 includes at least one communication interface 502, aprocessor 503, and program code instructions 505 that is stored inmemory 504 and executable by processor 503. The gateway 506 includes atleast one communication interface 507, a processor 508, and program codeinstructions 510 that is stored in memory 509 and executable byprocessor 508. Communication interface 502 in base station 501 may beconfigured to engage in a communication with communication interface 507in the gateway 506 via a communication path that includes at least onedigital link link 511. The digital link 511 is a bi-directional link.Communication interface 507 in the gateway 506 may also be configured toengage in a communication with communication interface 502 in the basestation 501. The base station 501 and gateway 506 may be configured tosend and receive data over the digital link 511. The communicationinterfaces 507 may include other interfaces for connecting to othernodes, such as packet network gateway. The communication interfaces 502may include other interfaces for connecting to other nodes, suchwireless interfaces for connection to wireless devices. Otheralternatives in which a base station or cell site gateway includesmultiple processors and multiple memories may also be implemented.

FIG. 6 is a block diagram of an integrated architecture for a basestation and a cell site gateway according to an exemplary embodiment.The integrated base station and cell site gateway 601 includes at leastone communication interface 602, a processor 603, and program codeinstructions 605 that is stored in memory 604 and executable byprocessor 603. Other alternatives in which a combined base station/cellsite gateway includes multiple processors and multiple memories may alsobe implemented.

FIG. 7 depicts a packet payload and headers according to an exemplaryembodiment. The packet 700 comprises a packet payload 703. The packetpayload 703 may include its own headers in an example embodiment. In oneembodiment, the cell site gateway may add two headers to the packet.Header 2 including label 2 (701) may identify the flow, such as apseudo-wire flow or an ATM or Ethernet flow, and another types of flow.Header 1 including label 1 (702) may identify a transmission port orpath such as a label switched path.

A wireless network site may comprise a first base station and a cellsite gateway. The first base station may communicate employing awireless technology with at least one wireless device. The wirelesstechnology may employ a protocol layer architecture comprising aphysical layer supporting simultaneous transmission employing aplurality of antennae in each sector of the first base station. Thefirst base station may communicate with a cellular network gatewaythrough a cell site gateway. The cell site gateway may comprise a firstinterface, a second interface a third interface, and a packet forwardinglayer. The first interface may be connected to the first base station.The second interface may be connected to a packet network gateway. Thethird interface may be connected to a signaling peer to exchange controlplane information to program a forwarding layer. The first control planeinformation may be employed to create a plurality of flow entriescomprising a first flow entry and a second flow entry. The first flowentry may comprise: a) a first match field for matching a firstplurality of packets received from the packet network gateway; b) afirst instruction field identifying at least one first instruction forprocessing the first plurality of packets. The second flow entry maycomprise: a) a second match field for transmitting a second plurality ofpackets to the packet network gateway; b) a second instruction fieldidentifying at least one second instruction for processing the secondplurality of packets. The signaling peer may exchange second controlplane information with the packet network gateway. The forwarding layermay transmit, to the first base station via the first interface. Thefirst plurality of packets may be associated to the first flow entry ifthe first plurality of packets matches the first match field. Theforwarding layer may transmit, to the packet network gateway via thesecond interface. The second plurality of packets associated to thesecond flow entry if the second plurality of packets matches the secondmatch field.

The signaling peer may be, for example, an off-line management server,and/or an off-line network controller. The signaling peer may exchangeinformation with the cell site gateway employing at least some of thefollowing mechanisms: signaling mechanisms for hardware programming;signaling mechanism for forwarding tables; and/or signaling mechanismfor device management and monitoring. The forwarding layer may drop aplurality packets if the plurality of packets do not match any matchfield in the plurality of flow entries. A flow entry may also include apriority for the packets, counters, time out value for aging theentries. The third interface may exchange control plane informationemploying a secure channel.

Cell site gateway, packet network gateway and cellular gateway mayoperate using open flow mechanism. Open flow equipment may comprise ofone or more flow tables and a group table, which perform packet lookupsand forwarding, and an open flow channel to an external controller. Theswitch may communicate with the controller and the controller may managethe switch via the open flow protocol. Using the open flow protocol, thecontroller may add, update, and delete flow entries in flow tables, bothreactively (in response to packets) and proactively. Each flow table inthe switch contains a set of flow entries; each flow entry may compriseof match fields, counters, and a set of instructions to apply tomatching packets.

Matching may start at the first flow table and may continue toadditional flow tables. Flow entries may match packets in priorityorder, with the first matching entry in each table being used. If amatching entry is found, the instructions associated with the specificflow entry are executed. If no match is found in a flow table, theoutcome depends on configuration of the table-miss flow entry: forexample, the packet may be forwarded to the controller over the openflow channel, dropped, or may continue to the next flow table.

Instructions associated with a flow entry either may contain actions ormodify pipeline processing. Actions may be included in instructionsdescribe packet forwarding, packet modification and group tableprocessing. Pipeline processing instructions may allow packets to besent to subsequent tables for further

processing and allow information, in the form of metadata, to becommunicated between tables. Table pipeline processing stops when theinstruction set associated with a matching flow entry may not specify anext table; at this point the packet may be modified and forwarded.

Flow entries may forward to a port. This may be a physical port, but itmay also be a logical port defined by the switch or a reserved port.Reserved ports may specify generic forwarding actions such as sending tothe controller, flooding, or forwarding using non-open flow methods,such as \normal” switch processing, while switch-defined logical portsmay specify link aggregation groups, tunnels or loopback interfaces.Actions associated with flow entries may also direct packets to a group,which specifies additional processing. Groups may represent sets ofactions for flooding, as well as more complex forwarding semantics (e.g.multipath, fast reroute, and link aggregation). As a general layer ofindirection, groups also enable multiple flow entries to forward to asingle identifier (e.g. IP forwarding to a common next hop). This mayallow common output actions across flow entries to be changedefficiently.

The group table may contain group entries. A group entry may contain alist of action buckets with specific semantics dependent on group type.The actions in one or more action buckets may be applied to packets sentto the group. Switch designers may implement the internals in any wayconvenient, provided that correct match and instruction semantics arepreserved. For example, while a flow entry may use an all group toforward to multiple ports, a switch designer may choose to implementthis as a single bitmask within the hardware forwarding table. Anotherexample is matching; the pipeline exposed by an open flow switch may bephysically implemented with a different number of hardware tables.

A Port may be where packets enter and exit the open flow pipeline. Itmay be a physical port, a logical port defined by the switch, or areserved port defined by the open flow protocol. A pipeline may be a setof linked flow tables that provide matching, forwarding, and packetmodifications in an open flow switch. A flow table may be a stage of thepipeline, contains flow entries. A flow entry may be an element in aflow table used to match and process packets. It may contain a set ofmatch fields for matching packets, a priority for matching precedence, aset of counters to track packets, and a set of instructions to apply. Amatch field may be a field against which a packet is matched, includingpacket headers, the ingress port, and the metadata value. A match fieldmay be wildcarded (match any value) and in some cases bitmasked. Ametadata may be a maskable register value that is used to carryinformation from one table to the next. Instructions may be instructionsthat are attached to a flow entry and describe the open flow processingthat happen when a packet matches the flow entry. An instruction eithermodifies pipeline processing, such as direct the packet to another flowtable, or contains a set of actions to add to the action set, orcontains a list of actions to apply immediately to the packet. An actionmay be an operation that forwards the packet to a port or modifies thepacket, such as decrementing the TTL field. Actions may be specified aspart of the instruction set associated with a flow entry or in an actionbucket associated with a group entry. Actions may be accumulated in theaction set of the packet or applied immediately to the packet. An actionset may be a set of actions associated with the packet that areaccumulated while the packet is processed by each table and that areexecuted when the instruction set instructs the packet to exit theprocessing pipeline. A group may be a list of action buckets and somemeans of choosing one or more of those buckets to apply on a per-packetbasis. An action bucket may be a set of actions and associatedparameters, defined for groups. A tag may be a header that may beinserted or removed from a packet via push and pop actions. An outermosttag may be the tag that appears closest to the beginning of a packet. Acontroller may be an entity interacting with the open flow switchesusing the open flow protocol. A meter may be a switch element that maymeasure and control the rate of packets. The meter may trigger a meterband if the packet rate or byte rate passing through the meter exceed apredefined threshold. If the meter band drops the packet, it may becalled a rate limiter

A flow table may comprise of flow entries. A flow table entry maycontain match fields, priority, counter, instructions, timeouts, and/orcookies. Match fields may be for matching against packets. These maycomprise of the ingress port and packet headers, and optionally metadataspecified by a previous table. A priority may be for matching precedenceof the flow entry. Counters may be updating/incrementing for a matchingpacket. Instructions may for modifying the action set or pipelineprocessing. Timeouts may be a maximum amount of time or idle time beforeflow a packet is expired by the switch. A cookie may be opaque datavalue chosen by the controller. It may be used by the controller tofilter. A flow table entry may be identified by its match fields andpriority.

Packet match fields may be extracted from the packet. Packet matchfields may be used for table lookups and may depend on the packet type,and may include various packet header fields, such as Ethernet sourceaddress or IPv4 destination address. In addition to packet headers,matches may also be performed against the ingress port and metadatafields. Metadata may be used to pass information between tables in aswitch. The packet match fields represent the packet in its currentstate, if actions applied in a previous table using the apply-actionschanged the packet headers, those changes may be reflected in the packetmatch fields. A packet may match a flow table entry if the values in thepacket match fields used for the lookup match those defined in the flowtable entry. If a flow table entry field has a value of ANY (or fieldomitted), it may match all possible values in the header. If the switchsupports arbitrary bitmasks on specific match fields, these masks maymore precisely specify matches.

The packet is matched against the table and the highest priority flowentry that matches the packet may be selected. The counters associatedwith the selected flow entry may be updated and the instruction setincluded in the selected flow entry may be applied. If there aremultiple matching flow entries with the same highest priority, theselected flow entry may be explicitly undefined. A flow table maysupport a table-miss flow entry to process table misses. The table-missflow entry may specify how to process packets unmatched by other flowentries in the flow table, and may, for example send packets to thecontroller, drop packets or direct packets to a subsequent table. Thetable-miss flow entry may be identified by its match and its priority,it wildcards match fields (or all fields omitted) and may have thelowest priority (0). The match of the table-miss flow entry may falloutside the normal range of matches supported by a flow table, forexample an exact match table would not support wildcards for other flowentries but may support the table-miss flow entry wildcarding allfields. The table-miss flow entry may not have the same capability asregular flow entry. Implementations may support for table-miss flowentries at minimum the same capability as the table-miss processing ofprevious versions of open flow: send packets to the controller, droppackets or direct packets to a subsequent table.

The table-miss flow entry may behave in most ways like any other flowentry: it does not exist by default in a flow table, the controller mayadd it or remove it at any time, and it may expire. The table-miss flowentry may match packets in the table as expected from its set of matchfields and priority. It may match packets unmatched by other flowentries in the flow table. The table-miss flow entry instructions areapplied to packets matching the table-miss flow entry. If the table-missflow entry directly sends packets to the controller using a controllerport, the packet-in reason may identify a table-miss. If the table-missflow entry does not exist, by default packets unmatched by flow entriesmay be dropped (discarded). A switch configuration, for example usingthe open flow Configuration Protocol, may override this default andspecify another behavior.

Counters may be maintained for each flow table, flow entry, port, queue,group, group bucket, meter and meter band. open flow-compliant countersmay be implemented in software and maintained by polling hardwarecounters with more limited ranges. An example may contain the set ofcounters defined by the Open flow mechanism. Duration may refer to theamount of time the flow entry, a port, a group, a queue or a meter hasbeen installed in the switch, and may be tracked with second precision.The receive errors field may be the total of receive and collisionerrors, as well as any others not called out. Counters may be unsignedand wrap around with no overflow indicator. If a specific numericcounter is not available in the switch, its value may be set to themaximum field value.

A flow entry may contain a set of instructions that are executed when apacket matches the entry. These instructions may result in changes tothe packet, action set and/or pipeline processing. A switch may not berequired to support all instruction types. The controller may also querythe switch about which of the optional instruction it supports. Theinstruction set associated with a flow entry may contain a maximum ofone instruction of each type. The instructions of the set may execute inthe order specified by this above list. Constraints may be that theMeter instruction may be executed before the Apply-Actions instruction,the Clear-Actions instruction may be executed before the Write-Actionsinstruction, and that Goto-Table is executed last. A switch may reject aflow entry if it is unable to execute the instructions associated withthe flow entry. In this case, the switch may return an unsupported flowerror. Flow tables may not support every match, every instruction andevery actions.

An action set may be associated with packets. This set may be empty bydefault. A flow entry may modify the action set using a Write-Actioninstruction or a Clear-Action instruction associated with a particularmatch. The action set may be carried between flow tables. When theinstruction set of a flow entry does not contain a Goto-Tableinstruction, pipeline processing may stop and the actions in the actionset of the packet are executed. An action set may contain a maximum ofone action of each type. The set-field actions may be identified bytheir field types, therefore the action set may contain a maximum of oneset-field action for each field type (i.e. multiple fields may be set).When multiple actions of the same type are required, e.g. pushingmultiple MPLS labels or popping multiple MPLS labels, the Apply-Actionsinstruction may be used. In an example, the actions in an action set maybe applied in the order specified below, regardless of the order thatthey were added to the set. If an action set contains a group action,the actions in the appropriate action bucket of the group are alsoapplied in the order specified below. The switch may support arbitraryaction execution order through the action list of the Apply-Actionsinstruction.

The output action in the action set may be executed last. If both anoutput action and a group action may be specified in an action set, theoutput action is ignored and the group action takes precedence. If nooutput action and no group action were specified in an action set, thepacket is dropped. The execution of groups may be recursive if theswitch supports it. A group bucket may specify another group, in whichcase the execution of actions traverses the groups specified by thegroup configuration.

In this specification, “a” and “an” and similar phrases are to beinterpreted as “at least one” and “one or more.”

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an isolatableelement that performs a defined function and has a defined interface toother elements. The modules described in this disclosure may beimplemented in hardware, software, firmware, wetware (i.e. hardware witha biological element) or a combination thereof, all of which arebehaviorally equivalent. For example, modules may be implemented as asoftware routine written in a computer language (such as C, C++,Fortran, Java, Basic, Matlab or the like) or a modeling/simulationprogram such as Simulink, Stateflow, GNU Octave, or LabVIEW MathScript.Additionally, it may be possible to implement modules employing physicalhardware that incorporates discrete or programmable analog, digitaland/or quantum hardware. Examples of programmable hardware include:computers, microcontrollers, microprocessors, application-specificintegrated circuits (ASICs); field programmable gate arrays (FPGAs); andcomplex programmable logic devices (CPLDs). Computers, microcontrollersand microprocessors are programmed employing languages such as assembly,C, C++ or the like. FPGAs, ASICs and CPLDs are often programmedemploying hardware description languages (HDL) such as VHSIC hardwaredescription language (VHDL) or Verilog that configure connectionsbetween internal hardware modules with lesser functionality on aprogrammable device. Finally, it needs to be emphasized that the abovementioned technologies are often used in combination to achieve theresult of a functional module.

The disclosure of this patent document incorporates material which issubject to copyright protection. The copyright owner has no objection tothe facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the Patent and Trademark Officepatent file or records, for the limited purposes required by law, butotherwise reserves all copyright rights whatsoever.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example, and notlimitation. It will be apparent to persons skilled in the relevantart(s) that various changes in form and detail can be made thereinwithout departing from the spirit and scope. In fact, after reading theabove description, it will be apparent to one skilled in the relevantart(s) how to implement alternative embodiments. Thus, the presentembodiments should not be limited by any of the above describedexemplary embodiments. In particular, it should be noted that, forexample purposes, the above explanation has focused on the example(s)employing LTE communication network. However, one skilled in the artwill recognize that embodiments of the invention may also be implementedin other communication systems, such as WiFi, WiMAX, or UMTS networks.

In addition, it should be understood that any figures which highlightthe functionality and advantages, are presented for example purposesonly. The disclosed architecture is sufficiently flexible andconfigurable, such that it may be utilized in ways other than thatshown. For example, the steps listed in any flowchart may be re-orderedor only optionally used in some embodiments.

Further, the purpose of the Abstract of the Disclosure is to enable theU.S. Patent and Trademark Office and the public generally, andespecially the scientists, engineers and practitioners in the art whoare not familiar with patent or legal terms or phraseology, to determinequickly from a cursory inspection the nature and essence of thetechnical disclosure of the application. The Abstract of the Disclosureis not intended to be limiting as to the scope in any way.

Finally, it is the applicant's intent that only claims that include theexpress language “means for” or “step for” be interpreted under 35U.S.C. 112, paragraph 6. Claims that do not expressly include the phrase“means for” or “step for” are not to be interpreted under 35 U.S.C. 112,paragraph 6.

What is claimed is:
 1. A wireless network site comprising: (a) a firstbase station, the first base station: (i) communicating employing awireless technology with at least one wireless device; and (ii)communicating with a cellular network gateway through a cell sitegateway; and (b) the cell site gateway, the cell site gatewaycomprising: (i) a first interface connected to the first base station;(ii) a second interface connected to a packet network gateway; (iii) athird interface connected to a control server to exchange control planeinformation to program a forwarding layer, the control plane informationcomprising at least one first label value and at least one second labelvalue, wherein the control server exchanges the control planeinformation with the packet network gateway; and (iv) the forwardinglayer for: (1) transmitting a second plurality of packets to the packetnetwork gateway employing the second interface; (2) receiving a firstplurality of packets from the packet network gateway employing thesecond interface; (3) attaching at least one of the at least one secondlabel to the second plurality of packets; and (4) removing at least oneof the at least one first label from the first plurality of packets. 2.The wireless network site of claim 1, wherein the forwarding layerfurther comprises swapping label on a third plurality of packets.
 3. Thewireless network site of claim 1, wherein the cell site gatewaycomprises of a path computation engine.
 4. The wireless network site ofclaim 1, wherein the cell site gateway exchanges the control planeinformation employing RSVP-TE via the third interface.
 5. The wirelessnetwork site of claim 1, wherein the cell site gateway exchanges thecontrol plane information employing MPLS-TP.
 6. The wireless networksite of claim 1, wherein the cell site gateway exchanges the controlplane information employing a label distribution mechanism via the thirdinterface.
 7. The wireless network site of claim 1, wherein the cellsite gateway comprises of routing functionality supporting a link staterouting protocol.
 8. A wireless network site comprising: (a) a firstbase station, the first base station: (i) communicating employing awireless technology with at least one wireless device; (ii)communicating with a second base station through a first cell sitegateway; and (iii) communicating with a cellular network gateway throughthe first cell site gateway; and (b) the first cell site gateway, thefirst cell site gateway comprising: (i) a first interface connected tothe first base station; (ii) a second interface communicating: (1) witha packet network gateway; and (2) with the second base station through asecond cell site gateway; (iii) a third interface connected to a controlserver to exchange control plane information to program a forwardinglayer, the control plane information comprising at least one first labelvalue, at least one second label value, and at least one parametercharacterizing the second interface; and (iv) the forwarding layer for:(1) transmitting a second plurality of packets to the packet networkgateway employing the second interface; (2) receiving a first pluralityof packets from the packet network gateway employing the secondinterface; (3) attaching at least one of the at least one second labelto the second plurality of packets; and (4) removing at least one of theat least one first label from the first plurality of packets.
 9. Thewireless network site of claim 8, wherein the forwarding layer furtherswaps at least one third label from a third plurality of packetsforwarded to the second cell site gateway.
 10. The wireless network siteof claim 8, wherein the packet network gateway is connected to thecellular network gateway.
 11. The wireless network site of claim 8,wherein the second plurality of packets are transmitted to the packetnetwork gateway via at least one intermediate network node.
 12. Thewireless network site of claim 8, wherein the at least one first labeland the at least one second label comprising: a) a label value; b) aclass of service; and c) bottom of label stack flag.
 13. The wirelessnetwork site of claim 8, wherein the cellular network gateway is an LTEServing Gateway.
 14. The wireless network site of claim 8, wherein thecellular network gateway is connected to an LTE Serving Gateway.
 15. Thewireless network site of claim 8, wherein the first base stationforwards at least one of the first plurality packets received from thecell site gateway to the second base station during the handoverprocedure.
 16. The wireless network site of claim 8, wherein the firstbase station forwards at least one of the first plurality of packetsreceived from the cell site gateway to the first cell site gatewayduring the handover procedure.
 17. A wireless network site comprising:(a) a first base station, the first base station: (i) communicatingemploying a wireless technology with at least one wireless device; and(ii) communicating with a cellular network gateway through a cell sitegateway; and (b) the cell site gateway, the cell site gatewaycomprising: (i) a first interface connected to the first base station;(ii) a second interface connected to a packet network gateway; (iii) athird interface connected to a control server to exchange control planeinformation to program a forwarding layer, the first control planeinformation employed to program at least: (1) a first flow entrycomprising a first match field; and (2) a second flow entry comprising asecond match field; and wherein the control server exchanges secondcontrol plane information with the packet network gateway; and (iv) theforwarding layer for: (1) transmitting, to the first base station viathe first interface, a first plurality of packets if the first pluralityof packets matches the first match field; and (2) transmitting, to thepacket network gateway via the second interface, a second plurality ofpackets if the second plurality of packets matches the second matchfield.
 18. The wireless network site of claim 17, wherein the controlserver is an off-line management server.
 19. The wireless network siteof claim 17, wherein the control server is an off-line networkcontroller.
 20. The wireless network site of claim 17, wherein thecontrol server exchanges information with the cell site gatewayemploying the following: a) signaling mechanisms for hardwareprogramming; b) signaling mechanism for forwarding tables; and c)signaling mechanism for device management and monitoring.